QUALITY EVALUATION OF FLOUR AND BISCUIT PRODUCED FROM SWEET POTATO AND ORANGE POMACE

This study exploited the food and functional potentials of orange pomace, a solid waste of orange juice production, in producing composite flours and acceptable biscuit. Orange pomace and sweet potato were processed into flour; at 0%, 5%, 10%, 15%, 20%, 25% and 30% levels, orange pomace flour was utilized to substitute sweet potato flour. Using conventional techniques, pasting and functional analysis were performed on the composite flours, likewise the proximate composition, antioxidant activity, physical characteristics and sensory acceptability of biscuits made from the composite flours were assessed. Wheat biscuit served as control. The pasting and functional qualities of the composite flours varied; addition of orange pomace considerably decreased peak viscosity (86.08 - 146.92 RVU) and breakdown viscosity (12.58 - 39.67 RVU) with varying impact on setback viscosity (43.00 - 62.75 RVU) and final viscosity (117.33 - 172.08 RVU). Biscuits produced from the composite flours were found to be significantly denser in ash (3.25 - 4.85%) and crude fibre (4.62 - 11.15%). The inclusion of orange pomace significantly increased DPPH, FRAP and total phenolic content with values ranging from 73. 23 to 83.44%, 4.85 to 9.92 mg vit. C/g and 17.93 to 24.75 mg GAE/g respectively. Biscuit produced from 85% sweet potato and 15% orange pomace composite flour showed significant higher acceptability and it compared favourably with the control. This study demonstrated that sweet potato-orange pomace composite flours could be used to make biscuits that people would find acceptable and that would support the waste-to-wealth drive as well as human fiber intake and its associated health benefits.